Permits are legal documents that the source must follow. They specify
what construction is allowed, what emission limits must be met, and often
how the source must be operated. They may contain conditions to make sure
that the source is built to match parameters in the application that the
permit agency relied on in their analysis. For example, the permit may
specify stack heights that the permit agency used in their analysis of
the source. Some limits in the permit may be there at the request of the
source to keep them out of other requirements. For example, the source
may take limits in a minor NSR permit to keep the source out of PSD. To
assure that sources follow the permit requirements, permits also contain
monitoring, recordkeeping, and reporting requirements.

Who Issues the Permits?

Usually NSR permits are issued by state or local air pollution control
agencies. The EPA issues the permit in some cases. State and local air
pollution control agencies may have their own permit programs that are
approved by EPA in the State Implementation Plan (SIP) or they may be
delegated the authority to issue permits on behalf of EPA. See the permit
agency contacts page for more information.